Abstract: The machine learning is a professional core course for artificial intelligence majors, and the course has the characteristics of strong engineering practice and complicated algorithms,which leads difficulty in mastering the knowledge in the course. The experimental teaching case of microblog hot topics research is designed according to machine learning project development process based on the result-oriented education concept of engineering education. After vectorizing the microblog text, the TF-IDF algorithm is used to assign weights to feature terms and construct a feature word matrix, and then the LDA model is used to obtain topics in different time windows using the EM algorithm, which is combined with visualization technology to discover hot topics on microblog. Experimental teaching practice of conducting this teaching case shows that the experimental case of using machine learning algorithm to solve social hot topics can not only cultivate students' practical engineering ability and engineering literacy, but also stimulate students' enthusiasm for independent learning of the course, which is an effective experimental teaching case design method.The experiment is highly comprehensive, which requires students' high mathematical abilities.

Key words: machine learning, teaching case design, OBE concept, microblog text, hot topics